ABSTRACT The Mouse Exercise and Metabolic Phenotyping Core (Core B) will facilitate the design and execution of the exercise experiments for Program Project members. Core B leverages the facilities and infrastructure of an original NIH-funded Mouse Metabolic Phenotyping Center (MMPC, www.mmpc.org) at Vanderbilt University and the specific expertise of its Director, David Wasserman, PhD in exercise physiology. Core B has already designed and executed exercise studies that have been recently published by the Elmquist, Zigman and Williams laboratories, in addition to designing all of the exercise paradigms used to generate the respective preliminary data for the current application. (see publications section within the individual projects). Core B will provide the following Exercise Protocols and Measurements: Exercise Protocols ? Incremental treadmill exercise test to assess peak O2 uptake and work capacity ? Analysis of endurance capacity utilizing motorized treadmills ? Perform acute high intensity interval exercise ? Perform chronic exercise training Measurements ? O2 uptake, CO2 output, and respiratory exchange ratio (RER) will be measured during or after exercise ? Body mass and composition ? Blood sampling through an indwelling catheter ? Analysis of liver and skeletal muscle glycogen content ? Analysis of biochemical signaling pathways ? Analysis plasma analysis of insulin, ghrelin, glucagon, triglycerides (TG), and non-esterified fatty acids (NEFA)